The present invention relates to a micro-machining dust removing device that removes the micro-machining dust generated when a workpiece, such as a photomask, is machined (for example, cut) using a probe tip, a micro-machining apparatus having the micro-machining dust removing device, and a micro-machining dust removing method.
In recent years, with advancement of nanotechnology, high technology of microscopic regions, such as nano-machines, electronic devices, and memories, attracts attention, and improvements in machining technology of the regions are requested. As one of such a micro-machining means, a method using a scanning probe microscope (SPM) attracts attention. Although the scanning probe microscope has not yet lead to the machining technology for mass production like semiconductor processes, this apparatus itself is an apparatus that is simple and comparatively low-cost, and yet has nano-scale high machining accuracy. Therefore, attention is paid to using the scanning probe microscope for a trial production technique and mask correction, etc. of fundamental devices in next-generation high-density memories, nano electronics, nano-machines, etc.
As the simplest method in the machining technology using this scanning probe microscope, a method of directly scratching (cutting) a surface, using a probe of an atomic force microscope (AFM) is known.
[Patent Document 1] JP-A-2005-266650
[Patent Document 2] JP-A-2004-318091
However, the following problems are left behind the above conventional method.
That is, since the conventional technique is mechanical cutting that directly scratches a workpiece with a probe, fine cutting dust, i.e., nano-scale micro-machining dust will be generated inevitably. Meanwhile, since this machined dust has a property of being charged at the time of cutting, it easily adheres again to a probe tip of the probe, the surroundings of cutting traces, etc.
Here, if the micro-machining dust has adhered to the cutting traces or their surroundings, the micro-machining dust become obstructive and consequently the cutting traces might be recognized visually. Thus, problems occur in that the subsequent additional machining cannot be performed, or machining with high repeatability cannot be performed.
Thus, in order to eliminate such problems to the utmost, there is a case that cleaning is performed after the machining to remove the micro-machining dust. Meanwhile, although this cleaning generally includes a physical removing method using a dry ice cleaner, or a removing method using wet cleaning, all these methods require a workpiece to be transferred to a separate apparatus after being once detached from a machining apparatus. Therefore, there is a problem in that time and efforts are taken, and throughput decreases. In addition to this problem, there is a disadvantage that the dry ice cleaner is very expensive, and the wet cleaning also requires much time.
Moreover, even if such cleaning is performed, there is also a possibility that the micro-machining dust cannot be removed, and the above disadvantage before the cleaning is performed cannot be overcome. Particularly in a case where the workpiece is a photomask formed on glass, transmittance may be lowered if micro-machining dust remains.
Meanwhile, when micro-machining dust adheres to the probe tip, the probe tip to be used as a cutting edge might be covered with the micro-machining dust. Thus, the workpiece will not be gradually shaved off. Particularly in a case where a diamond probe tip is used, the workpiece will not be promptly shaved off since a chemical change is caused if ferrous micro-machining dust adheres thereto. Further, even in a case where the micro-machining dust promotes oxidation, abrasion progresses, and thus the workpiece will also not be shaved off.
As described above, when micro-machining dust adheres to the probe tip or cutting traces, various disadvantages, such as significant decline in machining accuracy and deterioration on cutting quality, are caused. Therefore, a machining process requires micro-machining dust be removed by a new method instead of the cleaning having many disadvantages. However, a means that is effective to remove the micro-machining dust generated during machining in the machining process using the atomic force microscope has not yet been found out.
The invention has been made in consideration of such a situation, and the object of the invention is to provide a micro-machining dust removing device that can surely and efficiently remove the micro-machining dust generated during machining of a workpiece from a probe tip or machining traces without causing a decrease in throughput, a removal-processing apparatus having the micro-machining dust removing device, and a micro-machining dust removing method.